Wayne Rooney has been warned he risks being sent off in the World Cup should he repeat the tirade of abusive language launched at the referee in last night's warm-up game against Platinum Stars.

The England striker was shamed into issuing a post-match apology to the local official Jeff Selogilwe, handing him his No10 shirt as recompense, after shouting "fuck you" at the referee early in the second half. Rooney had been on the pitch only for a few minutes, but was already incensed that a series of niggly fouls committed by Kagiso Senamela and the former Tottenham Hotspur defender Mbulelo Mabizela had gone unpunished.

The USA, England's first opponents on Saturday, have already suggested they might play on Rooney's perceived fragile temperament with this an indication that the player can be on edge. "Rooney insulted me," said Selogilwe. "He said: 'Fuck you.' He is a good player when you see him on the television, but when you see him on the pitch he just keeps on insulting the referee.

"To me, it looks like Rooney insults people and fouls other players. If he insults a referee like me, then he will use that vulgar language to other referees as well. He must learn to control his temper. He could get sent off in the World Cup, especially if he uses this kind of language.

"Maybe the England players undermined this game and thought: 'This is just a friendly, we can do what we like and the referees are not that professional.' I was very disappointed in Rooney because he is my favourite player, but he will still be my favourite player. He apologised to me and gave me the shirt he was wearing at the end."

Rooney was dismissed in his last appearance at the World Cup finals, against Portugal in the quarter-final at Germany 2006, for kicking out at Ricardo Carvalho though his disciplinary record has improved as he has matured in the years since. He was booked only eight times last season, and has not been sent off since Manchester United's Premier League game at Fulham in March 2009. Indeed, he went through England's entire qualification campaign for South Africa without being cautioned.

However, his temper notoriously flares when frustration builds and, having missed the end of the domestic campaign with an ankle injury first sustained in the Champions League quarter-final at Bayern Munich and aggravated thereafter, Mabizela's attentions were clearly not welcome. "I think Wayne's temper is a good thing," said his team-mate Jermain Defoe, who was replaced by the United forward at half-time with England 1-0 up. "When you've got that fire in your belly as a player, if you take that away from him then he won't be the same player."

Selogilwe's own performance was decidedly erratic – a perplexed Jamie Carragher was booked for kicking the ball away, while Emile Heskey received a yellow card for an innocuous foul late on – given the nature of this warm-up game played to a crowd of about 7,000 locals who were admitted for free. Rooney recovered his poise enough to volley England's third goal after Defoe, two minutes in, and Joe Cole had earlier pierced the South African Premier Soccer League side's defences.

"It was a good run out," said Rooney. "I would have liked to have played a bit more of the game, but I was happy with the 45 minutes. We're ready. These games, against Japan, Mexico and today, have been preparation games. The big one's now on Saturday and I just can't wait. The sooner it comes the better."

Capello was unimpressed by his team's first‑half display but admitted some relief not to have picked up any injuries in his side's final game before their Group C opener against the USA on Saturday, with Rio Ferdinand watching from the bench. The Italian made 10 half-time substitutions, with only Joe Cole playing for 90 minutes, but appeared to play something approaching a first-choice back-line and central midfield in the first half – there remains the possibility that Jamie Carragher could still replace Glen Johnson at right-back – and his preferred forward line in the second.

That would see Heskey partner Rooney against the USA, with the new captain, Steven Gerrard, moved back to a deeper‑lying central midfield role alongside Frank Lampard. Robert Green appears to be edging towards starting that match given that David James, still nursing a slight knee problem, did not feature here. Gareth Barry was not named among the substitutes and does not expect to be involved in Rustenburg on Saturday as he continues his recovery from ankle ligament damage. "I've been told I'm not playing against USA to give me more time," Barry said last night. "I'll be back in full training with the team from tomorrow."